| hydrochloric acid | saltsyre |
| hydroculture | hydrokultur |
| hydroelectric energy | vandkraft |
| Hydroelectric plant | Vandkraft |
| Hydroelectric power | Vandkraft |
| hydroelectric power plant | vandkraftværk |
| Hydroelectricity | Vandkraft |
| hydrogen | brint |
| Hydrogen bond | Hydrogenbinding |
| Hydrogen bound | Hydrogenbinding |
| Hydrogen bridge bond | Hydrogenbinding |
| Hydrogen bridge linkage | Hydrogenbinding |
| Hydrogen cyanide | Blåsyre |
| Hydrogen peroxide | Hydrogenperoxid |
| hydrogen sulphide | svovlbrinte |
| hydrogeology | hydrogeologi |
| hydrographic basin | hydrografisk flodområde |
| hydrographic network | hydrografisk net |
| hydrography | hydrografi |
| Hydrolase | Hydrolase |
| Hydrolisis | Hydrolyse |
| hydrologic balance | vandbalance |
| hydrologic cycle | vands kredsløb |
| hydrologic disaster | hydrologisk katastrofe |
| hydrologic flow | vandstrøm |
| hydrology | hydrologi |
| hydrolysis | hydrolyse |
| hydrometeorology | hydrometeorologi |
| hydrometry | hydrometri |
| Hydronium | Hydronium |
| Hydrophile | Hydrofil |
| Hydrophilia | Hydrofil |
| Hydrophis belcheri | Belchers havslange |
| Hydrophyllaceae | Honningurt-familien |
| Hydropower station | Vandkraft |
| Hydrosphera | Hydrosfære |
| hydrosphere | hydrosfære |
| Hydrothermal synthesis | Krystallografi |
| Hydroxide | Hydroxid |
| Hydroxides | Hydroxid |
| Hydrus | Lille Søslange |
| hyena | hyæne |
| Hyenas | Hyæner |
| Hygelac | Chlochilaicus |
| hygiene | hygiejne |
| Hygroscopicity | Hygroskopi |
| Hyksos | Hyksos |
| Hyla | Løvfrøer |
| Hyles gallii | Snerresværmer |
| Hyllestad | Hyllestad |
| Hylobatidae | Gibboner |
| Hylotelephium telephium | Sankthansurt |
| Hylte Municipality | Hylte kommun |
| Hymen | Jomfruhinde |
| Hymenaios | Jomfruhinde |
| Hymenomycete | Basidiesvampe |
| Hymenoptera | Honningbi |
| hymenopteran | Hymenoptera |
| Hymenorrhaphy | Mødomsrekonstruktion |
| Hymenotomy | Hymenektomi |
| Hymer | Hymer |
| Hymir | Hymer |
| Hymiskviða | Hymiskviða |
